The major goal of this research project is to examine the physiologic and pharmacologic interactions of cholinergic and adrenergic nervous systems in the eye. After systematic alteration of cholinergic and adrenergic input to rabbit eyes, measurement of the resulting changes in pupillary diameter, intraocular pressure, and outflow facility in response to the adrenergic agents epinephrine, norepinephrine, and isoproterenol and the cholinergic agents pilocarpine and carbachol should provide much information in this direction. Several pertinent means are being utilized in order to achieve imbalances in cholinergic and adrenergic inputs to the anterior segment of the eye. These include (1) variation of the intensity of the physiologic stimulus, light; (2) surgical denervation procedures, including superior cervical ganglionectomy and ciliary ganglionectomy; and (3) acute and chronic administration of pharmacologic agents reducing or increasing the ocular levels of the neurotransmitters acetylcholine and norepinephrine. BIBLIOGRAPHIC REFERENCE: Colasanti, B.K., Chiu, P. and Trotter, R.R.: Supersensitivity and subsensitivity of the rabbit iris after superior cervical ganglionectomy. Abstracts of the Sixth International Congress of Pharmacology, Helsinki, P. 559, 1975.